Finely dice the green and red bell peppers and red onion. Halve the cherry tomatoes, cube the salami, and chop the mozzarella.

In a large pot, bring salted water to a rolling boil. Add the short pasta and cook until al dente, about 8-10 minutes. Drain the pasta thoroughly.

Transfer the warm pasta to a large mixing bowl. Toss in the diced peppers, onion, halved tomatoes, salami, black olives, cubed mozzarella, and grated Parmesan cheese.

Drizzle the Italian dressing over the pasta and vegetables, and gently toss until everything is evenly coated. Adjust seasoning with salt and pepper if needed.

Cover the bowl with plastic wrap or a lid and refrigerate for at least 1 hour. This allows the flavors to meld together.

Before serving, gently toss the pasta salad to redistribute ingredients. Add more dressing if it appears dry.